Fast switching hybrid igbt device with trenched contacts

ABSTRACT

A hybrid IGBT device having a VIGBT and LDMOS structures comprises at least a drain trenched contact filled with a conductive plug penetrating through an epitaxial layer, and extending into a substrate; a vertical drain region surrounding at least sidewalls of the drain trenched contact, extending from top surface of the epitaxial layer to the substrate, wherein the vertical drain region having a higher doping concentration than the epitaxial layer.

This application is a divisional of and claims the benefit of theearlier filing date of co-pending U.S. patent application Ser. No.12/977,297 filed on Dec. 23, 2010, the entire disclosure of co-pendingapplication Ser. No. 12/977,297 is herein incorporated by reference.

FIELD OF THE INVENTION

This invention relates in general to semiconductor devices, and moreparticularly, to an improved and novel device configuration forproviding a fast switching Lateral insulated gate bipolartransistor(IGBT), and a fast switching hybrid IGBT having a VerticalIGBT(VIGBT) and a Lateral DMOS(LDMOS) structures with trenched contactsachieving higher breakdown voltage and lower on-resistance as well ashigher switching speed.

BACKGROUND OF THE INVENTION

The insulated gate bipolar transistor (hereinafter IGBT) is anintegrated combination of a bipolar transistor and a metal oxidesemiconductor field effect transistor and has become commerciallysuccessful due to its superior on-state characteristics and excellentsafe-operating area. IGBTs in integrated circuits are commonlyconfigured as lateral insulated gate bipolar transistors (hereinafterLIGBTs) and fabricated using a planar process sequence to minimize costand complexity of the integrated circuit manufacturing operation.

FIG. 1A is a cross cross cross sectional view showing a conventionalLIGBT 100 of prior art. The LIGBT 100 of FIG. 1A comprises: a P-substrate 101; an N epitaxial layer 103 on top surface of theP-substrate 101; a P buried layer 102 with higher doping concentrationthan the P-substrate 101 and located at a part of the top surface of theP-substrate 101 and beneath an n+ source (cathode) region 107 near topsurface of the N epitaxial layer 103; a p++ source contact doped region105 provided in the N epitaxial layer 103 and adjacent to a p bodyregion 104 and the n+ source region 107. A channel region of theillustrated LIGBT 100 is formed near top surface of the p body region104 between the n+ source region 107 and the N epitaxial layer 103; a p+anode region 108 located near the top surface of the N epitaxial layer103 and spaced apart from the p region 104; a source metal 111 and adrain metal 113 contacted with the n+ source (cathode) region 107 andthe p++ source contact doped region 105, and the p+ anode region 108 byplanar contact, respectively. The LIGBT 100 of FIG. IA offers severalimportant advantages over lateral diffusion metal oxide semiconductor,including high current handling capabilities, low on-resistance and highbreakdown voltage. However, it has suffered from a significant drawbackof switching speed because there is no n+ drain region provided forremoval of electrons (minority carriers) during turn-off process. Duringturn-on process, the p+ anode region 108 injects holes (majoritycarriers) into drift region and the n+ source (anode) region 107 injectselectrons into the drift region through the channel to form alow-resistance plasma modulation region. During turn-off process, theholes in the plasma modulation region are removed by flowing through thep+ anode region 108 but the electrons are removed by recombination ofthe electrons and the holes. Therefore, the turn-off process isdetermined by the recombination of electrons, and since no contact isprovided for the removal of the electrons, the turn-off time isrelatively long in the range of 3-10 microseconds, while turn-on time ismuch less than 1 microsecond.

A typical prior art fast switching LIGHT 200 is shown in FIG. 1B.Similar fast switching LIGHTs are shown in U.S. Pat. No. 4,989,058.Besides those in common with the LIGHT 100 of FIG. 1A, the LIGHT 200 ofFIG. 1B comprises an additional n+ drain region 209 adjacent to the p+anode region 208 to remove the electrons (minority carriers) during theturn-off process as discussed above. Therefore, the turn-off time of theLIGHT 200 of FIG. 113 is shorter than that of the LIGHT of FIG. 1A.However, the LIGHT 200 has its own constrain which is that on-resistanceis significantly increased because triggered voltage Vds for holes(majority carriers) injection is larger than the typical value of 0.7 Vfor the LIGHT 100 as shown in FIG. 2 due to an additional resistanceR_(p) (as illustrated in FIG. 1B) existing underneath the p+ anoderegion 208 besides Rd (as illustrated in FIG. 1A and FIG. 1B). TheTriggered voltage Vds is: I*(R_(d)+R_(p))=IR_(d)+IR_(p)≈IR_(d)+0.7V >0.7 V, where I is the current flowing through the drift region to then+ drain region 209. From FIG. 2 it can be seen that, the triggeredvoltage Vds of the LIGHT 100 is about 0.7V and the triggered voltage Vdsof the LIGHT 200 is about 1.2 V as shown in FIG. 2.

Accordingly, it would be desirable to provide a new and improved LIGHTthat has both low on-resistance and high switching speed.

SUMMARY OF THE INVENTION

It is therefore an aspect of the present invention to provide a new andimproved LIGHT to solve the problems discussed above. According to thepresent invention, there is provided a LIGHT, comprising: a drain-anodeadjoining trenched contact penetrating through an insulating layer andextending into an epitaxial layer of a first conductivity type, directlycontacting to a drain region having the first conductivity type and ananode region of a second conductivity type; and said drain regionvertically contacting to said anode region along sidewall of thedrain-anode adjoining trenched contact.

By providing a LIGBT with the drain-anode adjoining trenched contactsdescribed above, please refer to a preferred embodiment LIGBT 300 shownin FIG. 3, the triggered voltage Vds is reduced to about 0.7 V asillustrated in FIG. 4, which is the same value as that of the LIGBT 100of FIG. 1A because no R_(p) exists in the LIGBT according to the presentinvention. Meanwhile, the on-resistance of the present invention islower than that of the LIGBT 100 of FIG. 1A, because there is currentflowing through from drain to source before the triggered voltage.Moreover, the switching speed of the present invention is as same asthat of the LIGBT 200 of FIG. 1B due to the drain region provided forthe removal of minority carriers.

In another preferred embodiment, the LIGBT according to the presentinvention further comprises: a trenched gate in active area; a source(cathode) trenched contact penetrating through the insulating layer anda source (cathode) region having the first conductivity type, andfurther extending into a body region of the second conductivity typewithin the epitaxial layer; and a heavily doped contact region of thesecond conductivity type within the body region and below the source(cathode) region, surrounding sidewall and bottom of the source(cathode) trenched contact.

In yet another preferred embodiment, the LIGBT according to the presentinvention further comprises: a planar gate; a source (cathode) trenchedcontact penetrating through the insulating layer and a source (cathode)region having the first conductivity type, and further extending into afirst body region having the second conductivity type within theepitaxial layer; a second body region disposed within said first bodyregion and at least surrounding bottom of said source region, havingsaid second conductivity type with doping concentration higher than saidfirst body region; a heavily doped contact region having the secondconductivity type within the second body region and below the source(cathode) region and surrounding sidewall and bottom of the source(cathode) trenched contact.

In yet another preferred embodiment, the LIGBT of the present inventionfurther comprises one or more detail features as below: the drain regionof the first conductivity type surrounds upper portion of the sidewallof the drain-anode adjoining trenched contact while the anode region ofthe second conductivity type surrounds lower portion of the sidewall ofthe drain-anode adjoining trenched contact and wraps around bottom ofthe drain-anode adjoining trenched contact; the LIGBT further comprisesa breakdown voltage enhancement doping region of the first conductivitytype wrapping around the anode region, wherein the breakdown voltageenhancement doping region has a doping concentration lower than thedrain region and higher than the epitaxial layer. Another preferredembodiment further comprises one or more detail features as below: theanode region of the second conductivity type surrounds upper portion ofthe sidewall of the drain-anode adjoining trenched contact while thedrain region of the first conductivity type surrounds lower portion ofthe sidewall of the drain-anode adjoining trenched contact and wrapsaround bottom of the drain-anode adjoining trenched contact; the LIGBTfurther comprises a breakdown voltage enhancement doping region of thefirst conductivity type wrapping around the anode region, wherein thebreakdown voltage enhancement doping region has a doping concentrationlower than the drain region and higher than the epitaxial layer. Thedrain-anode adjoining trenched contact is filled with Ti/TiN/Al orCo/TiN/Al or Ta/TiN/Al alloys, which also acts as a drain-anode metallayer. Alternatively, the drain-anode adjoining trenched contact isfilled with Ti/TiN/W or Co/TiN/W or Ta/TiN/W as metal plug connecting toan Al alloys layer as a drain-anode metal layer; the LIGBT furthercomprises a Ti or Ti/TiN layer underneath the drain-anode metal layer asan inter-metal contact resistance-reduction layer.

The inventive LIGBT is either discrete device on single chip orintegrated with a control IC on single chip.

According to another preferred embodiment, please refer to FIG. 11 for aIGBT 1000, there is provided a hybrid VIGBT(Vertical IGBT)-LDMOS,comprising: a drain trenched contact penetrating through an insulatinglayer and an epitaxial layer of a first conductivity type, and furtherextending into a substrate of a second conductivity type undereneath theepitaxial layer; a vertical drain region of the first conductivity typeadjacent to the drain trenched contact, extending from top surface ofthe epitaxial layer to top surface of the substrate or into thesubstrate, wherein the vertical drain region having a higher dopingconcentration than the epitaxial layer; and the vertical drain regioncontacting to a drain-anode metal layer on bottom surface of thesubstrate. Optionally, in some preferred embodiment, a buffer layer ofthe first conductivity type is offered between the substrate and theepitaxial layer, wherein the buffer layer has a higher dopingconcentration than the epitaxial layer, as shown in FIG. 11. In anotherpreferred embodiment, a vertical drain region surrounding sidewalls andbottom of the drain trenched contact does not contact to the substrate.

Another preferred embodiment has similar cross sectional view of theFIG. 11 except that the drain trenched contact penetrates the insulationlayer and extends into the epitaxial layer but does not further extendto the substrate. The drain region surrounds sidewalls and bottom of thedrain trenched contact and contacts to a drain metal over the insulationlayer through the metal plug filled into the drain trenched contact. Thedrain metal may connects to an anode metal on the bottom surface of thesubstrate through bonding wires, bonding ribbon or copper clips in apackage.

These and other objects and advantages of the present invention will nodoubt become obvious to those of ordinary skill in the art after havingread the following detailed description of the preferred embodiment,which is illustrated in the various drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention and together with the description serve to explain theprinciples of the invention. In the drawings:

FIG. 1A is a cross sectional view showing a conventional LIGBT of priorart.

FIG. 1B is a cross sectional view showing a fast switching LIGBT ofanother prior art.

FIG. 2 is a graph showing relationships between Ids and Vds of LIGBT inFIG. 1A and FIG. 1B.

FIG. 3 is a cross sectional view showing a preferred embodiment of thepresent invention.

FIG. 4 is a graph showing relationships between Ids and Vds of LIGBT inFIG. 3 and FIG. 1B.

FIG. 5 is a cross sectional view showing another preferred embodiment ofthe present invention.

FIG. 6 is a cross sectional view showing another preferred embodiment ofthe present invention.

FIG. 7 is a cross sectional view showing another preferred embodiment ofthe present invention.

FIG. 8 is a cross sectional view showing another preferred embodiment ofthe present invention.

FIG. 9 is a cross sectional view showing another preferred embodiment ofthe present invention.

FIG. 10 is a cross sectional view showing another preferred embodimentof the present invention.

FIG. 11 is a cross sectional view showing another preferred embodimentof the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 3 is a cross sectional view showing a LIGBT 300 according to apreferred embodiment of the present invention. The LIGBT 300 of FIG. 3is formed in an epitaxial layer 303 of a first conductivity type, heren-type, grown onto top surface of a semiconductor substrate 301 of asecond conductivity type, here p-type. A P buried layer 302 is locatedat a part of the top surface of the substrate 301 and beneath an n+source (cathode) region 307 which formed near top surface of theepitaxial layer 303, wherein the P buried layer 302 has a higher dopingconcentration than the substrate 301 and the n+ source (cathode) region307 has a higher doping concentration than the epitaxial layer 303. Afirst P body region 305 is formed within the epitaxial layer 303 andencompassing the n+ source (cathode) region 307 and forming a channelregion underneath a first insulating layer 315 near the top surface ofthe epitaxial layer 303. A second P body region 304 is formed within thefirst P body region 305 and at least surrounding bottom of the n+ source(cathode) region 307, having a doping concentration higher than thefirst P body region 305. A source (cathode) metal layer 311 of Al alloyspadded with a barrier layer of Ti/TiN or Co/TiN or Ta/TiN is filleddirectly into a source (cathode) trenched contact 317 which penetratesthrough a second insulating layer 314 and the n+ source (cathode) region307 and further extends into the second P body region 304 to contactwith the n+ source (cathode) region 307 and the second P body region304. Within the second P body region 304, a p+ heavily doped contactregion 306 is formed surrounding sidewall and bottom of the source(cathode) trenched contact 317 below the n+ source (cathode) region 307to reduce the contact resistance between the source (cathode) metal 311and the second P body region 304, wherein the p+ heavily doped contactregion has a higher doping concentration than the second P body region304. An n+ drain region 308 is formed near the top surface of theepitaxial layer 303 and spaced apart from the first P body region 305.and a p+ anode region 309 is formed within the epitaxial layer 303,below the n+ drain region 308. A drain-anode metal 313 of Al alloyspadded with a barrier layer of Ti/TN or Co/TiN or Ta/TiN is directlyfilled into a drain-anode adjoining trenched contact 316 whichpenetrates through the first insulating layer 315 and the n+ drainregion 308 and further extends into the p+ anode region 309 tovertically contact with the n+ drain region 308 and the p+ anode region309, wherein the n+ drain region 308 surrounds upper portion of thesidewalls of the drain-anode adjoining trenched contact 316 and the p+anode region 309 surrounds lower portion of the sidewalls of thedrain-anode adjoining trenched contact 316 and wraps around bottom ofthe drain-anode adjoining trenched contact 316. A gate metal 312 of Alalloys is filled directly into a gate trenched contact penetratingthrough the second insulating layer 314 to contact with a planar gate310 of doped poly-silicon layer.

FIG. 4 illustrates Ids-Vds characteristic comparison between LIGBT 300of FIG. 3 and LIGBT 200 of FIG. 1B, it shows that the triggered voltageof this invention has been reduced to a typical value of 0.7V withhigher switching speed.

FIG. 5 is a cross sectional view showing a LIGHT 400 according toanother preferred embodiment of the present invention which has asimilar configuration to the LIGBT 300 in FIG. 3 except that, the LIGHT400 of FIG. 5 additionally provides an n* breakdown voltage enhancementdoping region 418 wrapping around the p+ anode region 409 and contactingto the n+ drain region 408, wherein the doping concentration of the n*breakdown voltage enhancement doping region 416 is lower than that ofthe drain region 408 but higher than that of the epitaxial layer 403.The n* breakdown voltage enhancement doping region is disposedunderneath the n+ drain region or wrapping around both the p+ anoderegion and the n+ drain region.

FIG. 6 is a cross sectional view showing a LIGHT 500 according toanother preferred embodiment of the present invention which has asimilar configuration to the LIGBT 300 in FIG. 3 except that, the p+anode region 509 surrounds upper portion of the sidewall of thedrain-anode adjoining trenched contact 516 and the n+ drain region 508surrounds lower portion of the sidewall of the drain-anode adjoiningtrenched contact 516 and wraps around bottom of the drain-anodeadjoining trenched contact 516.

FIG. 7 is a cross sectional view showing a LIGHT 600 according toanother preferred embodiment of the present invention which has asimilar configuration to the LIGHT 500 in FIG. 6 except that, the LIGBT600 of FIG. 7 additionally provides an n* breakdown voltage enhancementdoping region 618 wrapping around the p+ anode region 609 and contactingto the n+ drain region 608, wherein the doping concentration of the n*breakdown voltage enhancement doping region 618 is lower than that ofthe drain region 608 but higher than that of the epitaxial layer 603.The n* breakdown voltage enhancement doping region may wraps around boththe p+ anode region and the n+ drain region as another preferredembodiment.

FIG. 8 is a cross sectional view showing a LIGBT 700 according toanother preferred embodiment of the present invention which has asimilar configuration to the LIGBT 400 in FIGS except that, the source(cathode) trenched contact 717, the drain-anode adjoining trenchedcontact 716 and the gate trenched contact are filled with a tungstenplug 721 padded by a barrier layer of Ti/TiN or Co/TiN or Ta/TiN torespectively contact with the source (cathode) metal 711, thedrain-anode metal 713 and the gate metal 712 of Al alloys which isoptionally padded by a inter-metal contact resistance-reduction layer ofTi or Ti/TiN.

FIG. 9 is a cross sectional view showing a LIGHT 800 according toanother preferred embodiment of the present invention. The LIGHT of FIG.9 is formed in an epitaxial layer 803 of a first conductivity type, heren-type, grown onto top surface of a semiconductor substrate 801 of asecond conductivity type, here p-type. At least a first type trenchedgate 804 in active area and at least a second type trenched gate 803 ingate contact area which are implemented by filling doped poly-siliconlayers in a plurality of gate trenches in the epitaxial layer 803. An n+source (cathode) region 807 are formed near top surface of the epitaxiallayer 803 and surrounding top portion of sidewalls of the first typetrenched gate 804, wherein the n+ source (cathode) region 807 has ahigher doping concentration than the epitaxial layer 803. A P bodyregion 805 is formed within the epitaxial layer 803 and encompassing then+ source (cathode) region 807 and forming a channel region along thesidewalls of the first type trenched gate 804, wherein the P body region805 surrounds lower portion of the sidewalls of the first type trenchedgate 804. Each of a plurality of source (cathode) trenched contacts 817filled with a tungsten plug 821 padded by a barrier layer of Ti/TiN orCo/TiN or Ta/TiN is penetrating through the insulating layer 815 and then+ source (cathode) region 807 and further extending into the P bodyregion 805. Underneath each of the source (cathode) trenched contact817, a p+ heavily doped contact region 806 is formed within the P bodyregion 805 and surrounding sidewall and bottom of the source (anode)trenched contact 817 below the n+ source (anode) region 807 to reducethe contact resistance between the tungsten plug 821 and the P bodyregion 805, wherein the p+ heavily doped contact region 806 has a higherdoping concentration than the P body region 805. An n+ drain region 808is formed near the top surface of the epitaxial layer 803 and spacedapart from the P body region 805, and a p+ anode region 809 is formedwithin the epitaxial layer 803 and below the n+ drain region 808,meanwhile, an n* breakdown voltage enhancement doped region 816 isformed contacting to the n+ drain region 808 and wrapping around the p+anode region 809, wherein the n* breakdown voltage enhancement dopedregion 816 has a doping concentration higher than the epitaxial layer803 but lower than the n+ drain region 808. A drain-anode adjoiningtrenched contact 816 filled with a tungsten plug 820 padded by thebarrier layer is penetrating through the insulating layer 815 and the n+drain region 808 and further extending into the p+ anode region 809. Agate trenched contact filled with a tungsten plug 822 padded by thebarrier layer is penetrating through the insulating layer 815 andextending into the doped poly-silicon layer within the second typetrenched gate 803. Onto the insulating layer 815, a gate metal 812, asource (cathode) metal 811 and a drain-anode metal 813 of Al alloyswhich is optionally padded by a resistance-reduction layer of Ti or TiNis formed to be electrically connected to the tungsten metal plug 822,the tungsten plug 821 and the tungsten plug 820, respectively. Anotherpreferred embodiment has a similar configuration to the LIGBT 800 exceptthat there is no n* breakdown voltage enhancement doping region.

FIG. 10 is a cross sectional view showing a LIGBT 900 according toanother preferred embodiment of the present invention which has asimilar configuration to the LIGBT 800 in FIG. 9 except that, a buriedoxide layer 902 is disposed between an epitaxial layer 903 and asubstrate 901 for further enhancing breakdown voltage.

FIG. 11 is a cross sectional view showing a hybrid IGBT comprisingVIGBT(Vertical IGBT)-LDMOS 1000 according to another preferredembodiment of the present invention. The hybrid VIGBT-LDMOS 1000 isformed in an epitaxial layer 1003 of a first conductivity type, heren-type, grown onto top surface of a semiconductor substrate 1001 of asecond conductivity type, here p-type. Between the epitaxial layer 1003and the substrate 1001, there is an N* buffer epitaxial layer 1002having higher doping concentration than the epitaxial layer 1003. Atleast a first type trenched gate 1004 in active area and at least asecond type trenched gate 1010 in gate contact area which areimplemented by filling doped poly-silicon layers in a plurality of gatetrenches in the epitaxial layer 1003. An n+ source (cathode) region 1007are formed near top surface of the epitaxial layer 1003 and surroundingtop portion of sidewalls of the first type trenched gate 1004, whereinthe n+ source (cathode) region 1007 has a higher doping concentrationthan the epitaxial layer 1003. A P body region 1005 is formed within theepitaxial layer 1003 and encompassing the n+ source (cathode) region1007 and forming a channel region along the sidewalls of the first typetrenched gate 1004, wherein the P body region 1005 surrounds lowerportion of the sidewalls of the first type trenched gate 1004. Each of aplurality of source (cathode) trenched contacts 1017 filled with atungsten plug 1021 padded by a barrier metal layer of Ti/TiN or Co/TiNor Ta/TiN is penetrating through the insulating layer 1015 and the n+source (cathode) region 1007 and further extending into the P bodyregion 1005. Underneath each of the source (cathode) trenched contact1017, a p+ heavily doped contact region 1006 is formed within the P bodyregion 1005 and surrounding sidewall and bottom of the source (anode)trenched contact 1017 below the n+ source (anode) region 1007 to reducethe contact resistance between the tungsten plug 1021 and the P bodyregion 1005, wherein the p+ heavily doped contact region 1006 has ahigher doping concentration than the P body region 1005. A gate trenchedcontact filled with a tungsten plug 1022 padded by the barrier layer ispenetrating through the insulating layer 1015 and extending into thedoped poly-silicon layer within the second type trenched gate 1003. AnN+ vertical drain region 1008 is formed adjacent to sidewalls of a draintrenched contact 1016, wherein the N+ vertical drain region 1008 isextending from top surface of the epitaxial layer 1003, penetratingthrough the epitaxial layer 1003 and the N* buffer epitaxial layer 1002and to top surface of the substrate 1001 while the drain trenchedcontact 1016 filled with a conductive plug 1020 of doped poly-silicon ortungsten plug is penetrating through the insulating layer 1005, theepitaxial layer 1003 as well as the N* buffer epitaxial layer 1002 andextending into the substrate 1001. Onto the insulating layer 1015, agate metal 1012, a source (cathode) metal 1011 which is optionallypadded by a resistance-reduction layer of Ti or TiN is formed to beelectrically connected to the tungsten metal plug 1022, the tungstenplug 1021, respectively. Onto bottom surface of the substrate 1001, adrain-anode metal 1013 such as Ti/Ni/Ag is formed connecting with the n+vertical drain region 1008 by the drain trenched contact 1016. Inanother preferred embodiment, the N+ vertical drain region 1008surrounding not only sidewalls but also bottom of the drain trenchedcontact 1016.

Another preferred embodiment has similar cross sectional view of theFIG. 11 except that the drain trenched contact penetrates the insulationlayer and extends into the epitaxial layer but does not further extendto the substrate. The N+ drain region surrounds sidewalls and bottom ofthe drain trenched contact and contacts to a drain metal over theinsulation layer through the metal plug filled into the drain trenchedcontact. The drain metal connects to an anode metal on the bottomsurface of the substrate through bonding wires, bonding ribbon or copperclips in a package.

Although the present invention has been described in terms of thepresently preferred embodiments, it is to be understood that suchdisclosure is not to be interpreted as limiting. Various alternationsand modifications will no doubt become apparent to those skilled in theart after reading the above disclosure. Accordingly, it is intended thatthe appended claims be interpreted as covering all alternations andmodifications as fall within the true spirit and scope of the invention.

1. A hybrid IGBT device having VIGBT and LDMOS structures comprising: atleast a drain trenched contact filled with a conductive plug penetratingthrough an insulating layer and an epitaxial layer of a firstconductivity type, and further extending into a substrate of a secondconductivity type undereneath said epitaxial layer; a vertical drainregion of said first conductivity type surrounding at least sidewalls ofsaid drain trenched contact, extending from top surface of saidepitaxial layer to said substrate, wherein said vertical drain regionhaving a higher doping concentration than said epitaxial layer; and saidvertical drain region contacting to a drain-anode metal layer on bottomsurface of said substrate.
 2. The hybrid IGBT of claim 1 furthercomprising: at least a trenched gate in active area; a source (cathode)trenched contact penetrating through the insulating layer and a source(cathode) region having said first conductivity type, and furtherextending into a body region of said second conductivity type withinsaid epitaxial layer; said source (cathode) region is formed near topsurface of said epitaxial layer and surrounding top portion of sidewallsof said trenched gate, encompassed in said body region; and a heavilydoped contact region having said second conductivity type within saidbody region and below said source (cathode) region surrounding sidewallsand bottom of said source (cathode) trenched contact.
 3. The hybrid IGBTof claim 1 further comprises a gate trenched contact penetrating throughsaid insulating layer and extending into a trenched gate in gate contactarea.
 4. The hybrid IGBT of claim I, wherein said trenched gate ispadded by a gate oxide layer and filled with a doped poly-silicon layer.5. The hybrid IGBT of claim 1, wherein said conductive plug filled intosaid drain trenched contact is doped poly-silicon.
 6. The hybrid IGBT ofclaim 1, wherein said conductive plug filled into said drain trenchedcontact is tungsten plug padded with a barrier metal layer.
 7. Thehybrid IGBT of claim I further comprising a buffer epitaxial layer ofsaid first conductivity type between said epitaxial layer and saidsubstrate, wherein said buffer layer has a higher doping concentrationthan said epitaxial layer.
 8. The hybrid IGBT of claim I wherein saiddrain-anode metal layer is Ti/Ni/Ag.
 9. A hybrid IGBT device havingVTGBT and LDMOS structures comprising: a drain trenched contact filledwith a conductive plug penetrating through an insulating layer andextending into an epitaxial layer of a first conductivity type on abuffer epitaxial layer of said first conductivity type above a substrateof a second conductivity type wherein said buffer epitaxial layer havingdoping concentration higher than said epitaxial layer; a vertical drainregion of said first conductivity type surrounding bottom and sidewallsof said drain trenched contact in said epitaxial layer, wherein saidvertical drain region having a higher doping concentration than saidepitaxial layer; said vertical drain region connecting to a drain metallayer over said insulating layer through said conductive plug filledinto said drain trenched contact bottom; and an anode metal disposed onthe bottom surface of said substrate.
 10. The hybrid IGBT device ofclaim 9 wherein said anode metal connects to said drain metal throughbonding wires, bonding ribbons or copper clips in a package.